Disputed. Most people use Erasmian pronunciation, which is described in all the Greek Primer PDFs here on Textkit. This web page has a list comparing Erasmian, probably ancient Athenian and biblical pronunciations.

secondly, writing in greek is like that of latin, from left to right, right?

For our purposes yes. Very ancient inscriptions can go either way, or even both directions.

thirdly, i hear there are a lot of irregular verbs in greek, is that true?

secondly, writing in greek is like that of latin, from left to right, right?

For our purposes yes. Very ancient inscriptions can go either way, or even both directions.

To add a word on a word, the very ancient Greeks had a pair of mirrored letters for each letters of the alphabet. For the two writing directions they chose. And the way of writing in both directions, called boustrophedon([face=SPIonic]boustrofhdo/n[/face]), was called like that because it resembled the way for a farmer to drive an ox to till the ground, hence 'an oxen-ploughing'.